Portable electric-arc light



E. HIRT.

PORTABLE ELECTRIC ARC LIGHT.

APPLICATION FILED JAN-2| I917.

Patented Mar. 15, 1921.

lnvez tifo'r PIORI'IIS PETERS. INC.. LITHD WASHINGTON. D C

EDWARD HIRT, OF WEYMOUTH, MASSACHUSETTS.

PORTABLE ELECTRIC-ARC LIGHT.

Application filed January 2, 1917.

To all whom it may concern:

Be it known that I, EDWARD Hrnr, a citizen of the United States, and a resident of lVeymouth, in the county of Norfolk and State of Massachusetts, have invented an Improvement in Portable Electric -Arc Lights, of which the following description, in connection with the acompanying drawings, is a specification, like characters on'the drawings representing like parts.

This invention relates to electric arc lamps and has for its object to provide a portable arc lamp capable of being carried in one hand. and especially adapted among other uses to be employed for furnishing the light necessary for making blue prints, photoprints and the like.

To this end, the electrodes or carbon penoils are secured in holders of slate or other insulating material, which are fastened to a supporting frame comprising two members, preferably pivoted together so as to be capable of adjusting the carbons as they are consumed, and which frame is capable of being carried in one hand and moved over the glass beneath which the blue print paper is placed. The electrodes are connected 7 with a suitable switch, preferably a plug switch capable of being inserted in the ordinary incandescent lamp socket, and between the electrodes and said plug switch is a resistance coil which may and preferably will be used as a heater for drying the blue prints.

These and other features of this invention will be pointed out in the claims at the end of this specification.

Figure 1 represents a portable arc lamp embodying this invention, and

Fig. 2, a side elevation looking toward the left in Fig. 1.

Referring to the drawings a, 6, represent two arms or members preferably of wood or other insulating material and curved at their inner ends, and preferably mounted to turn on a pivot pin 0, so as to adjust the carbon or other suitable pencils 10, 12, toward and from each other.

The arms a, Z), may be secured in their adjusted position by a thumb nut 13 engaging the pivot c, and adapted to frictionally clamp the said arms together in a manner well understood.

The arms or members a, I), carry at their outer ends holders for the carbon pencils 10,

Specification of Letters Patent.

Patented Mar. 15, 1921.

Serial No. 140,014.

12, which holders may be of like construction and each of which consists as herein shown of a stationary member 14, see Fig. 2, of slate or other insulating material and a movable member 15 of like material, between which the carbon pencil is clamped by a screw 16 extended through the members 14, 15, of the holder and through the arm to which said members are secured.

The stationary member 14 has secured to it a terminal block 17 of metal or other conducting material, which is preferably pro vided on its upper surface with a transverse recess, preferably curved to conform to the circular form of the carbon pencil, and the said block may be secured on the member 14 of the holder in any suitable manner, as by providing the block 17 with a threaded rod 20 which is extended through the member 14 and the arm a or 7) to which said member is secured, and is engaged by a suitable nut 21.

The terminal blocks 17 are electrically connected by insulated wires 22, 23, with the terminals of a switch, preferably a plug switch 24 of known construction, which is adapted to be screwed into the socket of an incandenscent lamp fixture (not shown). and one of the wires as 22 has included in it a resistance coil 25, which reduces the strength of the current flowing to the carbon pencils and which also acts as a heater to dry the blue print or other similar paper after it has been washed. The resistance coil 25 is of known construction and is mounted on a center pin 26, which is supported by a suitable frame preferably of sheet metal, which is shaped to form substantially parallel end walls 28 on which the pin 26 is supported, and a top wall 29, which is preferably provided with perforations 30 and upon which the wet blue print paper may be laid to dry, or said paper may be supported above the heater upon bent rods 31, 32, which are pivoted to the opposite sides of the end walls and are made of such size as to project above the top wall of the heater. The pivoted rods 31, 32, are capable of being moved toward and away from each other, so as to form an adjustable support for sheets of print paper of various sizes within limits, and also to serve as handles for carrying the heater. The end walls 28 may be provided with outwardly extended flanges 34 to form feet for the heater.

The carbon pencils 10, 12 may have cooperating with them a reflector 35, which is secured to a rod 36, rotatably mounted in a post 37, secured to one or? the arms as a, and

said rod may be secured in its adjusted position in said post by the frictional fit of said rod or in any other suitable manner. The Wires 22, 23, may and preferably will be laid in grooves 38 in the outer sides or edges of the arms and secured therein against displacement in any suitable manner.

In operation with the apparatus herein shown, the plug 24 is inserted in the lamp socket and the arms a, Z), are moved toward each other until the carbons 10, 12, are brought into contact with each other. The current is then turned on, and ii desired the carbons may be allowed to burn until the arc is of the proper length or the arms a, b, may be moved away from each other to draw the arc. The reflector 85 is'turned with re lation to the arc so as to deflect the ligl'it down upon the glass of the blue print frame (not shown) but which may be such as commonly used. and when the light is of the de sired intensity, the supporting frame (1-,, (1, is held by one hand of the operator and moved over the glass, thereby exposing the blue print paper to the action of the light to print the same, after which the print is removed, washed in the usual manner to develop it, and then placed on theheater to dry. The apparatus is especially adapted to be used by draftsmen in small concerns, offices and like places, and especially on dark days, and is a compact, inexpensive and highly citicient are light for the purpose of taking blue prints, photoprints and the like, and when not in use can be detached from the lamp socket and stored away in a small space. It will be observed that the light can be extinguished by merely separating the carbons to break the arc, thereby avoiding the use of a separate switch for this purpose.

I have herein shown one construction of apparatus embodying the inventiom'but it it not desired to limit the invention to the particular construction shown although it may be preferred.

Claims:

1. A portable arc light comprising a supporting frame consisting of arms having curved inner ends pivoted together and capable of being grasped by a hand 01' the operator and moved toward and from each other by the hand in which they are held, means cooperating with said pivot to fric tionally secure said arms in their adjusted positions, carbon holders of insulating material secured to the free ends of said arms to move therewith, carbon pencils carried by said holders and extended toward each other between said arms, and conductors carried by said arms and connected with said pencils.

2. A portable are light comprising a supporting frame consisting of arms having curved inner ends pivoted together and capable of being grasped by a hand of the operator and moved toward and from each other by the hand in which they are held, means cooperating with said pivot to trictionally secure said arms in their adjusted positions, carbon holders comprising stationary and movable members of insulating material secured to the said arms near the tree ends of the latter, carbon pencils clamped between the members of the carbon holders and extended toward each other, and conductors carried by said arms and connected with the stationary members of said carbon pencils.

In testimony whereof I have signed my name to this specification.

EDWARD mar. 

